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'(NoModeIJ 3 Sheets-Sheet 2 J. BAI RD. STEAM BOILER.

No.402,127. '.PdtentedApr.30,-1889.

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No. 402.127, Patented Apr. "so, 1889.

By Attorneys u FETER$ Pnmuuwgn mr. Wznhington. 0.0.

UNITED STATES) PATENT OFFICE.

JOl-IN BAIRD, OF NEIV YORK, NpY.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 402,127, dated April 30, 1889.

Application filed January 2, 1889.

To all whom it may concern.-

Be it known that I, JOHN BAIRD, mechanical engineer, of the city, county, and State of New York, have invented certain new and useful Improvements in Steam-Boilers, Ohiefi y Useful as Locomotive-Boilers, but Applicable also to Stationary and Marine Boilers; and I do hereby declare that the following, taken in connection with the drawings, is a full, clear, and exact description thereof.

Great difficulties are at present experiencedin the use of locomotive-engines, for the reak son that the boilers, being, as they are, of 1i mited size, are unable to supply sufficient steam to move heavy loads at the now required high speed, and this is especially the case in passenger-train engines. Moreover, the fire-boxes at present in use require constant repair, and the circulation in the water-spaces thereof is irregular, and mingled steam and Water rise into the space above the roof thereof. Further, the steam in ordinary locomotive-boilers, as a whole, is not sufficiently separated from the water, and water passes through the steampipe into the cylinders, wasting fuel and diminis'hing the quantity of steam which might otherwise be furnished by the boiler. Ihave attempted to remedy these evils, and believe Ihave to some extent succeeded.

According to my plans I make the fire-boxes of a series of arched tubes, thus doing away with all stay-bolts and insuring aregular circulation of the waterin the fire-box, and I prefer to make the roof or arched top of this fire-box lower than the water-space in the boiler proper, so as to deliver heated water, and perhaps steam formed inside the tubes, into the main boiler below the levehof .the water therein. I further, in combination with a fire-box thus made, form the boiler proper 0f two shells, one above the other and connected by proper pipes, and use the upper part of the upper shell as a steam-reservoir, thus securing a large steam-space, and one which, from the manner of its connection with both the tubes composing the fire-box and the lower shell, will probably be supplied with steam and water in such manner as to hold them separately or more completely separated than is usually the case. 4 i

In the drawings, which are in three sheets, in Sheet 1 thereof Figure 1 is a longitudt Serial No. 295,138.- (No model.)

nal vertical central section through a boiler and fire-box, the arrangement of the wheels upon which it is supported being indicated. Fig. 2 is a side elevation thereof; Fig. 3, a top view of the same; Fig. i, a transverse vertical section through the fire-box between the driving-wheels, showing, also, in elevation the tube-sheet of the boiler proper. Fig. 5 is a front, and Fig. 6 a rear, elevation of the same boiler.

In Sheet 2, Figs. 7, 8, and 9 are respectively a central longitudinal section, a side elevation, and a plan or top view of a boiler differing somewhat in the proportions of the firebox and shells from that represented on Sheet 1. Fig. 10 is a vertical cross-section through the fire-box of the boiler, taken just in front of the tube-sheet, and showing the tube-sheet and upper shell in elevation. Fig. 11 is a' similar section through the fire-box, but taken in front of the perforated brick wall, which acts as a smoke-burner in connection with the space behind it and in front of the tubes'heet. Fig.'12 is a front elevation of the same boiler; Fig. 13, a rear elevation of the same.

Sheet 3 contains drawings showing how my improved fire-box may be applied to a boiler having a single shell only. Figs. 14, 15, and 16 are respectively a central longitudinal vertical section through this boiler, a side elevation, and a plan or top View thereof. 7 F1g. 17 is a vertical transverse section through the fire-box, close in front of the tube-sheet, which is represented in elevation. Fig. 18 is a similar section taken near the front of the firebox, showing in elevation certain vertical tubes, to be described hereinafter. Fig. 19 1s an elevation of the front end of the boiler, and Fig. 20 one of the rear-ends thereof.

I have hitherto and will hereinafter call the fire-box end the front end of the boiler and f boiler represented on Sheet 1 the upper shell extends over the fire-box, and the latter is of the usual width and lies between the drivingwheels. In the boiler represented in Sheet 2 the upper shell does not extend over the tirebox, and the latter is so wide that it extends over the supporting-wheels; but these are differences of proportion only. The fire-box d in all the drawings is composed of a series of arched tubes, (1 d (1, applied togetherside by side. All the lower ends of these tubes connect with horizontal tubes (1 (Z and at points on or near the top of the arch of each tube they connect, by means of short vertical pipes c c 6, either directly with the upper shell of the boiler, as in Sheet 1, or indirectly by means of a tube, f, extending from the upper shell to the front of the firebox. I prefer to feed the water into the water-space forming the front end of the boiler, the water passing from it into the horizontal tubes at the bottom and sides of the fire-box. I can feed the water into both the horizontal tubes at the bottom and sides of the fire-box. The front g of the fire-box is composed of two sheets of boileriron united around their peripheries by another sheet or sheets of metal and stay-bolted in any usual way; and I prefer to connect the front ends of the tubes (Z d with this front, and to connect the feed-pipes with it.

The grate may be supported upon bearers attached to the tubes or some of them, and, when the Width of the fire-box will admit of it, I prefer to provide the front with two doors, as I have discovered that when the coal is changed first into one and then into the other side of the same fire-box it is burned more economically, and the joints of the tubes in the tube-sheet are less liable to become leaky.

I have shown no way of holding the arched tubes together or in place with reference to the boiler proper; but they may be inclosed in a sheet metal case attached to the boiler proper or the water-leg thereof, hereinafter described, and they may be of the shape outside of an ordinary fire-box, and provided with horizontal flanges on which the horizontal tubes rest. The arched tubes may also be secured by iron beams attached to the boiler-shell and provided with proper clamps, flanges, and bolts.

As the archway in the fire-box does not coincide with the tube-sheet of the boiler nor with the shell thereof, the boiler-shell is to be provided at its front end with an ordinary water-leg, h, which extends downward sidewise, and, if necessary, upward, so as to cover the rear end of the fire-box. I prefer to connect the horizontal tubes d d not only at their front ends with the front of the firebox, but also at their rear ends with the water-leg h. \Vhen the arched tubes composing the fire-box are supported by a continuous casing of sheet metal, I propose to pack the vacant spaces between the inside of this casing and the outside of the tubes with asbestus.

The lower shell of the boiler proper is to be furnished with the ordinary tubes and front and rear tube-sheets, and the upper shell, also, with tubes is k, which latter will serve to dry or superheat the steam. These tubes are shown in Figs; 1 and 7 as extending from head to head of the upper shell, and they open into the smoke-box at their rear ends, while at their front ends there is a cap upon the shell which covers the open ends of all the tubes. Deflectors Z Z are to be arranged, as shown, in the smoke-box and under the chimney. These deflectors will cause some of the products of combustion to pass forward through the lower tubes and return through the upper ones into the chimney.

In the drawings of Sheet 3 the shell of the boiler proper is cylindrical; but the fire-box is composed of the same arched tubes, with the top of the arches flattened, and each top portion of each tube is connected, by means of short vertical pipes e e c, with three pipes or tubes, f f, which latter open into the boiler proper. I have shown in this boiler the steampipe on supplied with uprising branches m m, each of which takes steam from a small steamdome, n.

I intend at times to furnish the fire-boxes with a contrivance that, to some extent, serves as a smoke-burner, like the wall 0, composed of perforated bricks or slabs, (shown in Figs.

7, 8, and 11,) and sometimes with additional fire-surface, as shown in Figs. 14, 17, and 18. This surface is, like that of the fire-box, composed of tubes 1) p. The upper ends of these tubes are in connection with one of the arched tubes of the fire-box, and their lower ends are connected with a transverse tube, (1, whose ends are to be connected in some proper way with the water-space of the boiler, the firebox, or both. This latter tube, q, may be closed at its ends and connected with the inclined tubes 8 s s, which at their forward ends are connected with the Water-space in front of the fire-box, and these tubes 8 s s then serve as grate-bars, or the ends of the tube q may be connected with the two horizontal tubes (1 LP, in which latter case ordinary grate-bars must be used.

As I prefer to preserve the full complement of the usual tubes in the shell of the boiler proper, and also to arrange the roof of the fire-box below the ordinary water-line in the boiler, I intend at times to cut away the upper part of some of the arched tubes that are nearest the front tube-sheet, as shown in Figs. 14:, 16, and 17, and to cover the open space thus left in the top of the fire-box with slabs of pottery or brick, t t, as shown in those figures, and also in Figs. 15, 18, and 19. By means of this eontrivanee I can introduce products of combustion from the fire-box into the upper rows of the usual tubes, u to, while the steam and hot water from the arched tubes enter the boiler at the tubes ff, below the water-level of the boiler, and the top of the arched tubes is also below that level.

I claim as of my own invention 1. In combination with a fire-box composed of arched tubes, substantially as described, a heating-surface composed of vertical tubes near the rear end of the fire-box, said combination being substantially such as specified.

2. A fire-box composed of arched tubes, as specified, in combination with a boiler proper composed of two horizontal connected shells, the combination being substantially as hereinbefore set forth.

3. A firebox composed of arohedtubes connected at their lower ends with horizontal tubes, substantially as described, in combination with a boiler-iron front, as described.

' 4. A fire-box composed of arched tubes connected at their lower end's'with horizontal tubes, in combination 'with a tube-sheet and a water-leg to the boiler, as described.

- JOHN BAIRD.

Witnesses:

AUGUSTUS MERRITT, LLOYD B. WIGHT. 

